Update CHANGELOG

CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 415b9f8..a130710 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ### Unreleased
 
  * [PR #16](https://github.com/magiconair/properties/pull/16): Keep gofmt happy
+ * [PR #18](https://github.com/magiconair/properties/pull/18): Fix Delete() function
 
 ### [1.7.0](https://github.com/magiconair/properties/tags/v1.7.0) - 20 Mar 2016